A fortune is not at stake, but this is the kind of story collector’s love—a rare 1794 signed letter from Napoleon Bonaparte found tucked in the pages of a 1900 leather bound biography of the general. A family had it on a bookshelf for nearly 40-years unaware of the letter that was discovered only when they brought the book to Waverly Auctions. High end estimate for the letter is $6,000 when it comes on the block tomorrow in Falls Church, Va.The book is one of 26 volumes on Napoleon. It’s likely no one will ever know how the one page letter got there. Historians say it was probably dictated by Napoleon to his secretary when he was a general, marked “personal,” and signed by him. It’s fine condition is attributed to being safely tucked away for at least the past 40-years.